Manufacturing method of a muffler assembly

ABSTRACT

A manufacturing method includes the steps as follow. Step 1: A pipe is cut to a length slightly longer than that of a muffling device. Step 2: The pipe has a lower end that is forged and formed as an exhaust pipe. Step 3: A muffling device that is wound as a spiral and received in a middle portion of the pipe. Step 4: The pipe has an upper end that is forged and formed as an inlet pipe. Step 5: The inlet pipe and the exhaust pipe are forged again to hold the muffling device in place in the middle portion of the pipe.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a manufacturing method, and more particularly to a manufacturing method of a muffler assembly.

[0003] 2. Description of Related Art

[0004] Conventional muffler assemblies in accordance with the prior art are usually classified several types as follow.

[0005] A. Straight pipe type: In this type, there are many muffler objects adhered on an inner periphery of the pipe.

[0006] B. Tortuous pipe type: This type uses the tortuous pipe to increase the muffler area for providing muffler effect.

[0007] C. Swell type: This type is similar to the straight type. However, the pipe of the swell type has a swell portion. The energy of the voice is changed and muffled when passing through the swell portion.

[0008] D. Resonance type: In this type, there is a resonance chamber made and directed against some certain voice frequencies for provide a resonance effect to achieve the objective of muffling.

[0009] The conventional muffler assembly comprises a, casino with two opposite holes defined in the casing. A corresponding one of the above mufflers in received in the casino via the holes in the casing. An inlet pipe and an exhaust pipe are respectively inserted into the two opposite holes of the casing. The inlet pipe and the exhaust pipe are positioned on the casino by welding. Most of the manufacturing processes of the conventional muffler assembly are weld such that the manufacturing processes are complicated, the work environment is bad and the manufacturing cost is hard to be reduced.

[0010] The present invention has arisen to mitigate and/or obviate the disadvantages of the conventional manufacturing method of a muffler assembly.

SUMMARY OF THE INVENTION

[0011] The main objective of the present invention is to provide an improved manufacturing method of a muffler assembly.

[0012] To achieve the objective, the manufacturing method in accordance with the invention comprises the steps as follow.

[0013] Step 1. A pipe is cut to a length slightly longer than that of a muffling device.

[0014] Step 2. The pipe has a lower end that is forged and formed as an exhaust pipe.

[0015] Step 3. A muffling device that is wound as a spiral and received in a middle portion of the pipe.

[0016] Step 4. The pipe has an upper end that is forged and formed as an inlet pipe.

[0017] Step 5. The inlet pipe and the exhaust pipe are forged again to hold the muffling device in place in the middle portion of the pipe.

[0018] Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0019]FIG. 1A is a plan view of a cylinder of a first embodiment of a muffler assembly that is made of a manufacturing method in accordance with the present invention before being manufactured.

[0020]FIG. 1B is a cross sectional view of the cylinder in FIG. 1A and forged to form an exhaust pipe;

[0021]FIG. 1C is a cross sectional of the first embodiment of the muffler assembly that a muffing device and muffling material is received in the cylinder in FIG. 1B;

[0022]FIG. 1D is a cross sectional of the first embodiment of the muffler assembly that the cylinder in FIG. 1C is forged to form an inlet pipe;

[0023]FIG. 1E is a cross sectional view that show the cylinder in FIG. 1D is forged again to hold the muffling device in place in the cylinder;

[0024]FIG. 2 is a cross sectional view of a second embodiment of a muffler assembly that is made of a manufacturing method in accordance with the present invention;

[0025]FIG. 3 is a cross sectional view of a third embodiment of a muffler assembly that is made of a manufacturing method in accordance with the present invention;

[0026]FIG. 4 is a cross sectional view of a fourth embodiment of a muffler assembly that is made of a manufacturing method in accordance with the present invention;

[0027]FIG. 5 is a cross sectional view of a fifth embodiment of a muffler assembly that is made of a manufacturing method in accordance with the present invention;

[0028]FIG. 6A is a cross sectional view of a six embodiment of a muffler assembly that is made of a manufacturing method in accordance with the present invention;

[0029]FIG. 6B is a side plan view of a muffling device in FIG. 6A;

[0030]FIG. 6C is a plan view of the muffling device in FIG. 6A that is expanded;

[0031]FIG. 6D is a funnel-shaped mold for forming the muffling device in FIG. 6A;

[0032]FIG. 7A is a cross sectional view of a seventh embodiment of a muffler assembly that is made of a manufacturing method in accordance with the present invention;

[0033]FIG. 7B is a side plan view of a muffling device in FIG. 7A;

[0034]FIG. 7C is a plan view of the muffling device in FIG. 7A that is expanded;

[0035]FIG. 7D is a stick-shaped mold for forming the muffling device in FIG. 7A; and

[0036]FIG. 8 is a plan view of another embodiment of the cylinder that is manufactured by the manufacturing method in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0037] A manufacturing method of a muffler assembly in accordance with the invention comprises the following steps.

[0038] Step 1. A cylinder is cut to a length slightly longer than that of a muffling device.

[0039] Step 2. The cylinder has a lower end that is forged and formed as an exhaust pipe.

[0040] Step 3. A muffling device that is wound as a spiral and received in a middle portion of the cylinder.

[0041] Step 4. The cylinder has an upper end that is forged and formed as an inlet pipe.

[0042] Step 5. The inlet pipe and the exhaust pipe are forged again to hold the muffling, device in place in the middle portion of the cylinder.

[0043] The spirally wound muffling device can increase the reflective face of different angles and raise the muffling effect. The outer periphery of the muffling, device is roughly manufactured or has multiple muffling materials adhered on the outer periphery of the muffling device when the muffling device is made of wire material. There are multiple holes with different sizes defined in the muffling device to raisin the muffling effect when the muffling, device is made of pipe material, plate material or a U-shape material.

[0044] The manufacturing processes of the muffling device are divided into the following types.

[0045] 1. Straight pipe type: The muffling, device is spirally manufactured and a cap is formed between every two adjacent spirals. The muffling device has a length smaller than that between the inlet pipe and the exhaust pipe, and has a diameter smaller than that of the inlet and the exhaust pipe. There is much muffling material adhered on an outer periphery of the muffling device. The above Step 3 is finally executed.

[0046] 2. Tortuous pipe type: The muffling device is spirally manufactured and has a length longer than that between the inlet pipe and the exhaust pipe such that the muffling, device forms several curves in the muffler assembly. There is no muffling material adhered on the outer periphery of the muffling device when the two spirals of the muffling device abut each other and there is much muffling material adhered on the outer periphery of the muffling device when a gap is form between the two adjacent spirals. The above Step 3 is finally executed.

[0047] 3. Swell type: The muffling device is spirally manufactured and a gap is formed between every two adjacent spirals. The muffling, device has two opposite ends each has a diameter smaller than that of the inlet pipe and the exhaust pipe. The muffling device has at least one swell portion formed in the middle portion of the muffler assembly. The above Step 3 is finally executed.

[0048] 4. Resonance type: The pipe is forged to form multiple resonance chambers for muffling voice and the above muffling, devices can be mounted in resonance chambers for promoting the muffling effect.

[0049] The above types of muffling device can be longitudinally and selectively connected for promoting muffling, effect.

[0050] With reference to FIGS. 1A-1E that show a first embodiment of the muffler assembly manufactured by the manufacturing method in accordance with the present invention. The first embodiment of the present invention comprises the following steps.

[0051] Step 1: A cylinder (1) is cut and has a length slightly longer than that of the muffling, device.

[0052] Step 2: The cylinder (1) has a first end (11), a second end opposite to the first end of the cylinder (1) and a middle portion (12) between the first end and the second end of the cylinder (1). The second end of the cylinder (1) is forged to form a tapering portion (13) and an exhaust pipe (14).

[0053] Step 3: A corresponding one of the above muffling devices is longitudinally received in the cylinder (1) and muffling material (18) is received between the muffling device (17) and an inner periphery of the cylinder (1) via the first end of the cylinder (1). The muffling device (17) has a first end received in the exhaust pipe (14).

[0054] Step 4: The first end of the cylinder (1) is forged and forms a tapering portion (15) and an inlet pipe (16). The muffling device (17) has a second end received in the inlet pipe (16).

[0055] Step 5: The cylinder (1) is forged again and the diameter of the cylinder (1) is changed to hold the muffling device (17) in place in the cylinder (1).

[0056] The noise orderly passes the inlet pipe (16), the muffling device (17), the muffling material (10) and the exhaust pipe (14), and is partially exterminated.

[0057] With reference to FIG. 2, it shows a second embodiment of the muffler assembly manufactured by the manufacturing method in accordance with the present invention. The muffler assembly (2) comprises a cylinder (21) and a muffling device longitudinally received in the cylinder (21). The manufacturing method of the cylinder (21) of the second embodiment is the same as that of the above first embodiment. The cylinder (21) is orderly disposed an inlet pipe (22), a first swell chamber (24), a second swell chamber (25), a resonance chamber (26) and an exhaust pipe (23). A muffling device (20) is spirally manufactured and longitudinally received in the cylinder (21). The muffling device (20) has a first end (2 a) securely received in the inlet pipe (22). The spirals of the first end of the muffling device (20) abut one another. A first section (2 b) integrally extends from the first end (2 a) of the muffling device (20) and is received in the first swell chamber (24). The spirals of the first section (2 b) are separated from one another. The first section (2 b) has a diameter Gradually increased relative to the exhaust pipe (23). A second section (2 c) integrally extends from the first section (2 b) of the muffling, device (20). The spirals of the second section (2 c) abut one another and abut an inner periphery of the cylinder (21) to separate the first swell chamber (24) from the second swell chamber (25). A third section (2 d) integrally extends from the second section (2 c) of the muffling device (20) and is received in the second swell chamber (25). The third section (2 d) has a diameter gradually reduced relative to the exhaust pipe (32) and the spirals of the third section (2 d) abut one another. A fourth section (2 e) integrally extends from the third section (2 d) of the muffling device (20) and is received in the second swell chamber (25). The spirals of the fourth section (2 e) of the muffling device (20) abut one another. A fifth section (2 f) integrally extends form the fourth section (2 e) and is received in the second swell chamber (25). The fifth section (2 f) of the muffling device (20) has a structure that is the same as that of the first section (2 b) of the muffling device (20). A sixth section (2 c) integrally extends from the fifth section (2 f) of the muffling device (20). The sixth section (2 g) has a structure that the same as the second section (2 c) of the muffling, device (20) and separates the second swell chamber (25) from the resonance chamber (26). A seventh section (2 h) integrally extends from the sixth section (2 g) and is received in the resonance chamber (26). The seventh section (2 h) of the muffling, device (20) has a structure that is the same as that of the third section (2 d) of the muffling device (20). The muffling device (20) has a second end (2 i) integrally extending from the seventh section (2 h) thereof and securely received in the exhaust pipe (23) of the cylinder (2). The spirals of the second end (2 i) of the muffling device (20) are separated from one another.

[0058] The sound wave swells and is partially exterminated in the second section (2 c) of the muffling device (20) and the first swell chamber (24) after passing the inlet pipe (22), the first end (2 a) and the first section (2 b) of the muffling device (20). The sound wave is compressed and partially exterminated in the third section (2 d) and the fourth section (2 e) of the muffling device (20). The sound wave swells and is partially exterminated in the fifth section (2 f) of the muffling, device (20) and the second swell chamber (25). The sound wave is compressed and partially exterminated in the sixth section (2 g) and the seventh section (2 h). The sound wave occurs a resonance and is partially exterminated in the resonance chamber (26). Finally, the exterminated sound wave passes through the second end and the exhaust pipe (23) of he cylinder (21).

[0059] With reference to FIG. 3, it shows a third embodiment of the muffler assembly manufactured by the manufacturing method in accordance with the present invention. The third embodiment of the present invention has a structure that is on the contrary of the above second embodiment of the present invention. The muffler assembly (3) of the third embodiment comprises a cylinder (31) and a muffling device (30) longitudinally received in the cylinder (31). The cylinder (31) is orderly disposed an inlet pipe (32), a resonance chamber (34), a first swell chamber (35), a second swell chamber (36) and an exhaust pipe (33). The muffling device (30) is orderly disposed a first end (2 a) secured in the inlet pipe (32) of the cylinder (31), a first section (2 b), a second section (3 c), a third section (3 d), a fourth section (3 e), a fifth section (3 f), a sixth section (3 g), a seventh section (3 h) and a second end (3 i) secured in the exhaust pipe (33) of the cylinder (31).

[0060] The sound wave occurs a resonance and is partially exterminated in the resonance chamber (34) after passing through the inlet pipe (32) and the first end (3 a) of the muffling device (30). The sound wave swells and partially exterminated in the first swell chamber (35) after passing through the first section (3 b), the second section (3 c) and the third section (3 d) of the muffling device (30). The sound wave is compressed and partially exterminated when passing through the fourth section (3 e) of the muffling device (30). The sound wave swells and is partially exterminated in the second chamber (36) after passing through the fifth section (3 f), the sixth section (3 g) and the seventh section (3 h) of the muffing device (30). The sound wave is compressed and partially exterminated when passing through the second end (3 i) of the muffling device (30). The exterminated sound wave is exhausted via the exhaust pipe (33) of the cylinder (31).

[0061] With reference to FIG. 4, it shows a fourth embodiment of the muffler assembly (4) that is manufactured by the manufacturing method in accordance with the present invention. The muffler assembly of the embodiment comprises a cylinder (41) has a first end forged to form an inlet pipe (42) and a second end forged to form an exhaust pipe (43). A muffling device (44) is received in the cylinder (41) and muffling material (45) fully received between the muffling device (44) and an inner periphery of the cylinder (41). The muffling device (44) is spirally made of pipe material and has a length longer than that of the cylinder (41) such that muffling device (44) forms multiple curves after being mounted in the cylinder (41). The muffling device (44) has multiple through holes (44 a) defined therein such that the sound wave is partially exterminated via the through holes (44 a) and the muffling material (45) when the sound wave passes through the muffling device (44).

[0062] With reference to FIG. 5, it shows a fifth embodiment of the muffler assembly manufactured by the manufacturing method in accordance with the present invention. The muffler assembly (5) of the embodiment comprises a cylinder (51) having a first end forged to form an inlet pipe (52) and a second end forced to form an exhaust pipe (53). The cylinder (51) is orderly disposed a first resonance chamber (54), a second resonance chamber (55), a swell chamber (56) and a third resonance chamber (57). A muffling device (58) is longitudinally received in the cylinder (51) and has two opposite ends respectively secured in the inlet pipe (52) and the exhaust pipe (53) of the cylinder (51). The muffling device (58) is orderly disposed a first swell chamber (58 a) separating the first resonance chamber (54) from the second resonance chamber (55), a second swell chamber (58 b) separating the second resonance chamber (55) from the swell chamber (56) and a third swell chamber (58 c) separating the swell chamber (56) from the third resonance chamber (57). The first swell chamber (58 a) communicates with the inlet pipe (52) and the third swell chamber (58 c) communicates with the exhaust pipe (53). The first swell chamber (58 a) has a first through hole (58 d) defined to communicate the first swell chamber (58 a) and the first resonance chamber (54), and a second through hole (58 e) defined to communicate the first swell chamber (58 a) and the second resonance chamber (55). The second swell chamber (58 b) has two through holes (58 f, 58 g) defined to communicate the second swell chamber (58 b) and the swell chamber (56) of the cylinder (51). The third swell chamber (58 c) has two first through holes (58 h, 58 i) defined to communicate the third swell chamber (58 c) and the swell chamber (56) of the cylinder (51), and a second through hole (58 j) defined to communicate the third swell chamber (58 c) and the third resonance chamber (57).

[0063] The sound wave occurs a resonance and is partially exterminated in the first resonance chamber (54) after passing through the inlet pipe (52) and the first through hole (58 d). The sound wave swells in the first swell chamber (58 a) and is partially exterminated. The sound wave occurs a resonance and partially exterminated in the second resonance chamber (55) after passing through the second through hole (58 e). The sound wave swells and partially exterminated in the second swell chamber (58 b). The sound wave swells and partially exterminated in the swell chamber (56) after passing through the two through holes (58 f, 58 c) in the second swell chamber (58 b). The sound wave is compressed and partially exterminated when passing the two first through holes (58 h, 58 i). The sound wave swells and is partially exterminated in the third swell chamber (58 c) after passing through the two first through holes (58 h, 58 i). The sound wave occurs a resonance and is partially exterminated in the third resonance chamber (57) after passing through the second through hole (58 j) in the third swell chamber (58 c). Finally, the exterminated sound wave is exhausted via the exhaust pipe (53).

[0064] With reference to FIGS. 6A-6D, it shows a sixth embodiment of the muffler assembly manufactured by the manufacturing method in accordance with the present invention. The muffler assembly (6) of the embodiment comprises a cylinder (61) having a first end forced to form an inlet pipe, a second end forged to form an exhaust pipe (63) and a swell chamber (67) defined in the cylinder (61) between the two opposite ends of the cylinder (61). A muffling device (64) is longitudinally received in the swell chamber (67) and the exhaust pipe (63). The muffling device (64) is made of a metal strap that is spirally wound along an outer periphery of a funnel-shaped mold (66) to form a passage (65) in the muffling device (64). A series of through holes (64 a) is defined in the muffling device (64). Consequently, the sound wave swells and is partially exterminated in the swell chamber (67) and Gradually compressed for being partially exterminated when passing the through holes (64 a) of the muffling device (64). Finally, the exterminated sound wave is exhausted via the exhaust pipe (63) of the cylinder (61).

[0065] With reference to FIGS. 7A-7D, it shows a sixth embodiment of the muffler assembly manufactured by the manufacturing method in accordance with the present invention. The muffler assembly (7) of the embodiment comprises a cylinder (71) having a first end forged to form an inlet pipe (72), a second end forced to form an exhaust pipe (73) and a swell chamber (77) defined in the cylinder (71) between the two opposite ends of the cylinder (71). A muffling device (74) is longitudinally received in the swell chamber (77) and the exhaust pipe (73). The muffling device (74) is made of a tapered plate that is spirally wound along an outer periphery of a stick-shaped mold (76) to form a passage (75) in the muffling device (74). Consequently, the sound wave swells and is partially exterminated in the swell chamber (77) and gradually compressed for being partially exterminated when passing the passage (75) of the muffling device (74). Finally, the exterminated sound wave is exhausted via the exhaust pipe (73) of the cylinder (71).

[0066] With reference to FIG. 8, it shows another embodiment of the cylinder. The cylinder (91) of the embodiment comprises a first end forged to form an inlet pipe (92) and a second end forged to form an exhaust pipe (93). The cylinder (91) has multiple annular grooves (95) and multiple longitudinal grooves (94) defined in an outer periphery of the cylinder (91). The annular grooves (95) and the longitudinal grooves (94) can strengthen the structure of the cylinder (91) and provide reflective faces to the muffle assembly to promoting the muffling effect of the present invention.

[0067] Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed. 

What is claimed is:
 1. A manufacturing method of a muffler assembly comprising the following steps: step 1: a cylinder cut to a length slightly longer than that of a muffling device; step 2: the cylinder having a lower end that forged and formed as an exhaust pipe; step 3: a muffling device that is wound as a spiral and received in a middle portion of the cylinder; step 4: the cylinder having an upper end that is forged and formed as an inlet pipe; and step 5: the inlet pipe and the exhaust pipe being forged again to hold the muffling device in place in the middle portion of the cylinder.
 2. The manufacturing method as claimed in claim 1, wherein the muffling device comprises multiple spirals separated from one another, a first end secured in the inlet pipe of the cylinder and a second end secured in the exhaust pipe, muffling material fully received in the cylinder.
 3. The manufacturing method as claimed in claim 1, wherein the muffling device has a length longer than that of the cylinder such that muffling device multiple curves after being mounted in the cylinder.
 4. The manufacturing method as claimed in claim 2, wherein the muffling device has a length longer than that of the cylinder such that muffling device multiple curves after being mounted in the cylinder.
 5. The manufacturing method as claimed in claim 1, wherein the muffling device has a changeable diameter to form multiple swell chambers and resonance chambers.
 6. The manufacturing method as claimed in claim 5, wherein the muffling device divides the cylinder into multiple swell chambers and resonance chambers.
 7. The manufacturing method as claimed in claim 1, wherein the cylinder has multiple annular grooves and multiple longitudinal grooves defined in an outer periphery of the cylinder to strengthen the structure of the cylinder and provide reflective faces to the muffler assembly to promoting the muffling effect.
 8. The manufacturing method as claimed in claim 2, wherein the cylinder has multiple annular grooves and multiple longitudinal grooves defined in an outer periphery of the cylinder to strengthen the structure of the cylinder and provide reflective faces to the muffler assembly to promoting the muffling effect.
 9. The manufacturing method as claimed in claim 3, wherein the cylinder has multiple annular grooves and multiple longitudinal grooves defined in an outer periphery of the cylinder to strengthen the structure of the cylinder and provide reflective faces to the muffler assembly to promoting the muffling effect.
 10. The manufacturing method as claimed in claim 5, wherein the cylinder has multiple annular grooves and multiple longitudinal grooves defined in an outer periphery of the cylinder to strengthen the structure of the cylinder and provide reflective faces to the muffler assembly to promoting the muffling, effect.
 11. The manufacturing method as claimed in claim 6, wherein the cylinder has multiple annular grooves and multiple longitudinal grooves defined in an outer periphery of the cylinder to strengthen the structure of the cylinder and provide reflective faces to the muffler assembly to promoting the muffling effect. 